My home mini-NAS

I’ve been getting increasingly edgy about the backup strategy we use at home.

My work backups are a lot more comprehensive: auto-snapshots, sending/receiving to a ZFS pool on SWAN, with hg clones of important workspaces stored on an NFS-backed home directory with its own separate backups performed by Sun IT.

At home though, we were storing most of our photos on my aging 2002 17″ iMac. There, when I remembered, I’d kick off a manual rsync of the contents of the mac to a 3.5″ 160gb ide disk containing a single ZFS pool attached to an OpenSolaris laptop via a USB enclosure.

– you can see the two approaches differ pretty significantly.

Added to this, the missus got a 1080p video camera for Christmas, and I figured a little extra storage would be handy. So, I decided it was time to get another computer at home that I could use as a small NAS box. I also figured that if this box was going to be left on a lot of the time, it ought to be power efficient. Along with that, wouldn’t it be good if it was capable of doing tasks other than just storing data?

I wanted at least a mirrored ZFS pool for the data, and a separate disk to run the OS from. Looking around a lot of the major consumer computer vendors, none that I could find were selling small, power efficient computers that could fit 3 disks. If any consumer-oriented computer vendors are out there, I’m sure there’s a market to be tapped here?

The best I could come up with, was a single-disk computer attached to a separate consumer NAS device. The trouble is, that NAS likely wouldn’t be running ZFS, and that was a non-starter for me.

So, I embarked on building my own. I’d seen a few good posts about building small NAS systems around an Atom processor and a mini-itx motherboard and decided to give it a go.

I went for an Atom board with an ION chipset, thinking that despite the newer D510 chips using slightly less power, they weren’t much faster than the dual-core Atom 330 and having Nvidia graphics meant I could use the box as a desktop as well as providing a stable storage platform. I didn’t really investigate AMD-based mini-itx boards: some of their chips look pretty low-power, and ECC ram would have been nice. Maybe next time.

I’d read some good reviews of the Chenbro 4-disk case, but cost was a factor here: the case I eventually went with was a lot cheaper: two hot-swap SATA disks and space for one internal disk was enough for me. I’ve read suggestions that the case can actually fit another disk if you’re willing to hack about a bit, and I could potentially also ditch the DVD drive and bolt on another 3.5″ disk if I needed more space. For now, 3 disks is enough.

I planned to use a ZFS mirror on the two hot-swap disks, and leave the OS on the internal disk. Yes, a terrabyte disk is a lot for an OS, but in my experience, you can never have enough scratch space.

I’d not built a PC in a long time, but this was pretty straightforward – my only quandry is whether I really need to connect the two fans at the back of the case: the motherboard doesn’t seem to get that hot during use, but for now, they’re staying connected, just in case. They’re not that loud.

Installing OpenSolaris nv_131 went without a hitch: I just needed to make sure the SATA disks were set to AHCI mode in the bios. I found and filed 6920337 pretty early on, and was thankful to get a fixed driver within 24h of my filing the original bug: much appreciated Rachel!

Otherwise, all is working well – the system has enough poke to run day-to-day desktop tasks: which for me, is several terminal windows, a bunch of browser windows, pidgin, Evolution and Netbeans. I’ve also tried fullscreen mp4 playback with totem and the Fluendo gstreamer plugins, and it can manage them just fine.

I’ve yet to plug the system into a power meter to see how efficient it is – I’ll add a comment to this post as soon as I find out.

That case looks cool. That little CPU (or is it a northbridge fan?) looks like it could be noisy though – I’ve been thinking about the completely fanless atom motherboards to get sound levels down. Is the fan noise bearable?

Yep, that’s a CPU fan – it’s very quiet. I’ve heard it ramp up a few times, but 99.9% of the time, you don’t notice it at all. The case fans beneath the power supply are a bit noisier though, but still absolutely bearable.

All that said, I don’t think I’d want this box sitting beside my TV (unless it was buried in a cupboard somewhere) – any of the single-disk fanless mini-itx cases would probably be a better fit there.

The things that need cooling just as much as the motherboard are the disks. Cook them and you loose all your data so make sure you have good airflow over the drives before you remove or turn off any fans.

It’s interesting seeing pictures of the insides of other OpenSolaris home made NAS boxes as it bangs home just how good Sun hardware is! Mine is the same, functional but not pretty.
I gave up with the mini system when the power supply failed. The power supply was not replaceable so a whole new box was required and so I returned to the world of towers which at least are not quite so cramped on the inside.

There’s a fan on the front of the case which blows air over the hotplug disks, so I might be ok with just that (but yes, also realise ‘might’ is not a good word when dealing with reliability (hence the initial desire to buy, not build – having experienced engineers work these things out for me would have been a lot nicer)

Running snv_132 with my home directory on the mirrored 2×1.5tb pool, logged into the desktop and at rest, I was measuring a fairly constant 50w.

Pushing the system a little more (running a zpool scrub on both pools, and running four ‘while true ; do ; done ;’ loops in a terminal, and flipping the display in compiz to moderately stress the graphics chip) the most I could push it to was about 65w.

I didn’t have that long with the power meter unfortunately, and haven’t done any investigation into tuning the system to try to further reduce power usage (spinning down the disks when idle might be an area to investigate, for example)

hi Michael, sorry, it’s been ages since I put this together and I’ve lost and forgotten the original price for the system.

I did link each component in the list above to the original item online, but most of those appear to dangle now. Your best bet is to use those as a guide, and see what the current prices are for the equivalent or (very likely) better components these days, or better yet, see if there are any pre-built systems out there that work out of the box.

Hi there. I just built something similar. I’ve got one ide drive that I am using for the OS and will be putting in just one SATA drive for now.

The back fan seems to run constantly and while not a real noise problem (it will be in a room that is infrequently used), I am also worried about the energy use, as I would like to leave the server on all the time.

Are you still running your fans? Do you know if there is some way to have them only go one when needed?

I think you could possibly disconnect one of the case fans if the noise is bothering you, but I’d definitely monitor the system temperature in that case – cooking disks is not good.

I know that the fan on the heatsink on my motherboard can rattle a bit too from time to time (though it’s been quiet of late) I’d say eventually, I’ll be buying new (quieter) fans all-round, but since this system stays in my home office, I’m not too concerned about it. At some stage, perhaps I’ll get a dedicated htpc, but that’ll likely have a small solid-state disk, and be completely fanless – this system happily serves content over wifi/gigabit ethernet to anything that’s listening. The Network Is The Computer, after all :-)